Apparatus for manufacturing pretensioned, reinforced concrete sections



2,962,785 REINFCRCED Dec. 6, 1960 J. M. YOUNG APPARATUS FCRMANUFACTURING PRETENsIoNED CONCRETE SECTIONS 2 Sheets-Sheet 1 Filed Aug.18. 1955 WYE . INVENTOR. B /72 ORNE YS Dec. 6, 1960 J. M. YOUNG2,962,785

APPARATUS FR MANUFACTURING PRETENSIONED, REINFORCED CONCRETE SECTIONSFiled Aug. 18, 1955 2 Sheets-Sheet 2 United States Patent APPARATUS FORMANUFACTURING PRETEN- SIGNED, REINFORCED CONCRETE SECTIONS James M.Young, West Allis, Wis., assgnor to West Allis Concrete Products Co.Inc., West Allis, Wis., a corporation of Wisconsin Filed Aug. 18, 1955,Ser. No. 529,272

3 Claims. (Cl. 25-1) This invention relates to improvements in apparatusfor manufacturing pre-tensioned, reinforced concrete sections.

In the manufacture of concrete sections, such as elongated pre-tensionedconcrete planks, it is important to obtain a high quality concrete and agood compaction around the tensioned reinforcing wires. Thesereinforcing wires are usually embedded in the layer of concrete which ispoured rst, and prior to the pouring of any other layers it is importantthat the concrete be properly compacted around the wires. Thispre-stressed lower layer of a concrete plank is the most importantcomponent if the plank is used as a structural member such as for roughflooring or roofing. Heretofore machnes for manufacturing concretesections have failed to provide for a proper compaction of the bottomlayer.

It is a general object of the present invention to provide, in anapparatus for manufacturing concrete Sections, improved means forcompacting the first poured layer of concrete around the reinforcingwires to thereby greatly improve the quality of the linal product.

A further object of the invention is to provide in 'an apparatus asabove described, means for creating rapid vibrations whereby fluentportions of the concrete may be caused to liow into all of the voids andwhereby particles of sand or aggregate may lind their most compactposition alongside one another.

A further object of the invention is to provide in an apparatus of theclass described, a pair of tamping members, both operable on the firstpoured layer of concrete, the front tamper being adapted topreliminarily tamp the freshly poured layer, and the rear tamper beingadapted to elect a final compaction of the concrete around the tensionedreinforcing wire.

A further object of the invention is to provide in an apparatus as abovedescribed vibrating mechanism connected to each tamping member whichmechanism may be used independently of or in conjunction with thetamping action.

A still further object of the invention is to provide a device as abovedescribed wherein the vibrators are detachably connected to the shoes ofthe tamping members.

A further object of the invention is to provide in a device as abovedescribed, means whereby the front and rear tampers may be independentlyadjusted to bring about an accurate control of density and other factorswhich affect the quality of the nal product.

A still further object of the invention is to provide an apparatus asabove described having improved mechanism for driving the tampers.

With the above and other objects in view, the invention consists of theimproved apparatus for manufacturing concrete sections, and all of itsparts and combinations, as set forth in the claims, and all equivalentsthereof.

In the accompanying drawing, in which the same reference numeralsdesignate the same parts in all of the views:

rice

Fig. 1 is a fragmentary side elevational view of an apparatus formanufacturing elongated concrete sections, such as concrete planks,illustrating the tampers for tamping and compacting the first pouredlayer of concrete;

Fig. 2 is an enlarged side elevational view of the tampiug andcompacting mechanism, parts being broken away to foreshorten the view,and other parts being broken away and shown in section;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2, parts beingbroken away;

Fig. 4 is a fragmentary elevational view looking at the rear of thefront tamping member; and

Fig. 5 is a transverse sectional view through a complete concrete plank.

Referring more particularly to the drawing, the numer 10 designatesgenerally an apparatus for manufacturing elongated pretensioned,reinforced concrete :sections such as concrete planks, said apparatusincluding a bin 11 having a bottom opening 12. The bin is adapted tocontain a concrete producing mixture 13 of high quality, said mixtureincluding aggregate and cement'ng matef rial. This mixture is adapted toform the bottom layer 14 of a concrete plank, such as the plank shown incross section in Fig. 5.

The apparatus also includes another bin 15 having a bottom opening 16.The bin 15 is adapted to contain a mixture containing a light-weightaggregate for forming the middle layer 17 (see Fig. 5). There may alsobe a third bin, not shown, for depositing a top or linishfng layer ofsuitable quality concrete such as the layer 18 of Fig. 5. The presentinvention is concerned with the apparatus for tamping, vibrating andcompacting the bottom layer 14.

As is well known in apparatus of this type, the appa-` ratus 10 may besuitably mounted for movement in the direction indicated by the arrow inFig. l, so that an elongated section such as a plank may beprogressively poured as the apparatus is moved.

Referring more particularly to the improved tamping and compactingapparatus, there may be suitable supports, preferably in the form ofinverted channels 19 which extend between the bins 11 and 15. Extendngtransversely of the supports 19 is a suitable support such as aninverted channel 2) on which -a gear box 21 is mounted. An electricmotor 22, which may also be supported on the channel 20, is adapted todrive a shaft 23 which extends into the gear box through a suitablebearing 24. Mounted rigidly on the shaft 23 is a worm 25 which mesheswith a wormwheel 26 mounted rigidly on a shaft 27. The shaft 27 isjournalled for rotation in bearings 23 and 29, the latter beingsupported on a transverse channel 3l) which is in turn supported on thechannels 19.

Keyed to the shaft 27, in front of the gear box 21, is an eccentric disc31 which is rotatable within a ring 32. Projecting upwardly from thering 32 is a rod section 33 having threading 34 thereon. The rod section33 is con# nected to an upper rod section 35, having threading 36, bymeans of a manually operable turnbuckle 37. The upper end of the rodsection 35 is connected by a clevis 38 with a horizontal support 39.

Depending from each end of the horizontal support 39 and pivotallyconnected thereto as at 40 are rods 41. The latter are guided forslidable movement in bearing members 42 which may be supported on thechannels 19. The lower ends of the rods 41 are formed with clevises 43which are pivotally connected by pins 44 with upwardly projecting eyedlugs 45 of a front tamping member 46, as shown in Fig. 4. 1

It will be noted from Fig. 2 that the tamping member 46 is L-shaped incross section and that its bottom is formed with spaced, transverse,inverted U-shaped recesses 47 which are adapted to produce convex ribs48 on the bottom layer 4of concrete, as shown in Fig. 5.

. Also keyed to the shaft 27, behind the gear box 21, is anothereccentric disc 49 which is rotatable within a ring 50. The eccentric 49is preferably disposed so that it projects oppositely from the eccentricdisc 31. Depending from the ring 50 is a rod section 51 having athreaded portion 52. Another rod section 53, which is threaded as at 54,is connected by a manually operable turnbuckle 55 with the rod section51. The lower end of the rod section 53 is in the form of an eye 56, andthe latter is connected by a pin 57 between the spaced ears 58 of aconnection member 59. The lower end of the member 59 has an opening 60through which a rod 61 extends. The outer ends of the rod 61 extendrotatably through openings in upwardly projecting lugs 62 of a reartamping member 63. The bottom of the rear tamping member 63 has the sameshape as is shown in Fig. 4 for the bottom of the front tamping member46.

The rod 61 also extends rotatably through openings in the forward endsof guide arms 64. The rearward ends of said guide arms are pivoted tothe bin as at 65 to thereby brace the rear tamping member whilepermitting up and down reciprocating movement.

' Projecting upwardly from each of the tamping shoes 46 and 63 arespaced apertured lugs 66, as shown in Figs. 2 and 4. These lugs aredetachably connected by nuts and bolts 67 with apertured lugs 63 whichdepend from vibrators 69. Each vibrator may be of any suitable type. Itis preferred, however, to use a vibrator of the general type illustratedon the shoe 63 of Fig. 2. This type of vibrator may include a weight 70slidable vertically on a rod 71 under the inuence of the changingmagnetic poles 72 and 73. The vibrators may be electrically energized inany suitable manner. One vibrator of a suitable type is known as theCleveland vibrator. These vibrators are capable of producing between1800 and 3600 vibrations per minute.

Operation In use of the improved apparatus, as the machine moves alongin the direction of the arrow of Fig. l, a concrete forming mixture fromthe bin 13 is discharged from the bottom opening 12 to pour thebottommost layer 14 of a concrete plank such as the plank shown in Fig.5. This layer is poured over pre-tensioned steel reinforcing wires 66 asis clear from Figs. 1 and 5. With the electric motor 22 in operation,the shaft 27 is rotated to cause an up and down reciprocating movementto be imparted to the upwardly projecting rods 33-35. Through the upperhorizontal member 3?', this causes an up and down movement of thedepending rods 41. Inasmuch as the rods are attached to the front tamper46, the latter moves up and down to tamp the surface of the concrete andform it in accordance with the pattern 47 shown at the bottom of Fig. 4.

At the same time, the rear tamper 63, which is in an opposite phase, isbeing reciprocated. Normally, the turnbuckle 55 for the rear tamper isadjusted so that the rear tamper, when in its lowermost position, issomewhat lower than the front tamper when the latter is in its lowermostposition. Thus a nal compaction is obtained by the operation of the reartamper, and the amount of compaction may be controlled by the adjustmentof the member 55. It is thus apparent that a very good compaction can beobtained around the pre-ten sioned reinforcing wires 66, and that thisaccurately controlled tamping and compaction, which is independent oftampers for any of the other layers, produces a very high qualityconcrete in the bottom layer which concrete is prestressed by beingformed around the wires. Unless the concrete is of high quality,prestressing cannot be successfully accomplished. As a result of thepresent apparatus, which gives accurate control over the density andquality of the bottom layer, the finished plank of Fig. 4 is capable ofwithstanding all of the stresses to which it may be subjected when usedas a roofing or flooring member in a building.

While the tampers may .be used as above described, without vibrators toproduce good results when working with certain materials, neverthelessit is very advantageous when working with certain other types ofmaterials to employ the vibrating action. When the vibrators are not tobe used, the bolts i67' may be removed and the vibrators detached, or ifpreferred, the vibrators may be left in connected condition, but notenergized.

If the vibrators are to be employed, they may be used either in additionto the tamping action, or inde pendently thereof. When vibration is tobe used alone, without tamping, then the shoes are adjusted to about thesame level with, however, the front shoe 46 slightly higher. The shoesare then kept in this position and the vibrators are operated. Whenworking with certain types of material, usually for the bottom layer 14,the Vrapid vibrations cause the fluent portions of the concrete to flowinto all of the voids and tend to cause particles of sand or aggregateto nd their most compact position alongside one another. Thus a veryrefined control of compaction may be obtained to increase the quality ofthe resulting product.

Various changes and modifications may be made without departing from thespirit of the invention, and all of such changes are contemplated as maycome within the scope of the claims.

What I claim is:

l. In an apparatus for manufacturing concrete sections and having amovable bin for progressively discharging a layer of concrete, a shaftrotatably supported behind said bin for movement therewith, means forrotating said shaft, said shaft projecting rearwardly in the line ofmovement of the bin, a first eccentric disc on said shaft, a ring withinwhich said disc is rotatable, a rst tamping member positioned to engagethe concrete layer, push rods projecting upwardly from said tampingmember, a cross member connecting said push rods above said rotatableshaft, means between said ring and cross member for causing up and downmovement of the cross member when said shaft is rotated, a secondeccentric disc on Said shaft behind the rst disc, a ring within whichsaid second disc is rotatable, a second tamping member positioned toengage the concrete layer behind the rst tamping member, and an upwardlyprojecting actuating connection between said second tamping member andthe ring which surrounds said second eccentric disc.

2. In an apparatus for manufacturing concrete sections and having amovable bin for progressively discharging a layer of concrete, a shaftrotatably supported behind said bin for movement therewith, means forrotating said shaft, said shaft projecting rearwardly in the line ofmovement of the bin, a first eccentric disc on said shaft, a ring withinwhich said disc is rotatable, a first tamping member positioned toengage the concrete layer, push rods projecting upwardly from saidtamping member, a cross member connecting said push rods above saidrotatable shaft, an elongated actuating member between said ring andcross member for causing up and down movement of the cross member whensaid shaft is rotated, means for varying the length of said actuatingmember, a second eccentric disc on said shaft behind the rst disc, aring within which said second disc is rotatable, .a second tampingmember positioned to engage the concrete layer behind the rst tampingmember, an elongated actuating member connecting said second tampingmember and the ring which surrounds said second eccentric disc, andmeans for varying the length of said last-mentioned elongated actuatingmember.

3. In an apparatus for manufacturing multi-layer concrete sections withthe use of pre-tensioned wires, said 5 apparatus having a bin movable inthe direction of extent References Cited in the lile of this patent ofsaid wires for progressively discharging a layer of con- UNITED STATESPATENTS crete over said Wires, tarnping apparatus connected to interlockwith the grooves therein. 357,591 Great Britain Sept. 25, 1931

